1. Field of the Invention
The present invention relates generally to the field of diagnosis and therapy of pelvic floor muscle disorders. More specifically, the present invention relates to pelvic floor function diagnostic and therapeutic station that can be used for diagnosis and treatment of pelvic floor muscle disorders.
2. Description of the Related Art
The pelvic floor muscles (PFM) form the floor of the pelvic basin and performs two major functions, an elevator function for pelvic organs and constrictor function for three orifices, urethra, vagina and anal canal. The elevator function of the pelvic floor supports the pelvic viscera and is probably important for the prevention of rectal, vaginal and bladder prolapse. Constrictor function, on the other hand is involved in the closure mechanism of urethra, vagina and anal canal. In individuals with normal pelvic muscle function, the pelvic floor muscle contracts simultaneously and this contraction precedes the increase in abdominal pressure as an unconscious automatic co-contraction (1,2). This contraction can be described as a cranial movement of the pelvic floor and closure around the urethra, vagina and anal canal. Pelvic floor muscle weakness can thus cause prolapse of pelvic organs and incontinence of urine, feces and poor vaginal closure. Therefore physical therapists often target the pelvic floor muscle for management of urinary and fecal incontinence, and other pelvic-floor disorders.
Measuring pelvic floor muscle strength is important not only in the diagnosis of impaired pelvic floor muscle function but also to evaluate the recovery of pelvic floor muscle function after therapeutic intervention. There are several devices that can measure pelvic floor muscle strength, they include, vaginal devices to measure the electromyographic signals of pelvic floor muscles, perineal dynamometer, various types of balloons, strain gauge and force transducers to measure vaginal closure strength. However none of these devices measure constrictor and elevator functions of pelvic floor muscles precisely. Furthermore, these devices cannot measure the length tension curve of the constrictor and elevator function of the pelvic floor muscle. It is important to measure the length tension relationship of pelvic floor muscles because this relationship is an important indicator of the actual strength of these muscles. Furthermore, to treat pelvic floor muscle weakness, it is often necessary to train pelvic floor muscles via biofeedback therapy.
There are two major problems with vaginal pressure measurements. First, air filled balloons and water filled balloons, used by most of the investigators, do not measure absolute pressures. Through the work of several investigators it became clear in 1970's that infusion manometry is a better technique to measure absolute pressure in sphincters, esophagus and other parts of GI tract. Secondly, vagina is approximately 10 cm long; a portion of it lies above pelvic diaphragm and a portion in the hiatus of pelvic diaphragm. None of the techniques used in the published literature made any attempt to distinguish pressures in different portions of the vaginal canal. It is likely that the segment of vagina located above pelvic diaphragm will reflect intra-abdominal pressure and the segment located in pelvic diaphragm hiatus will actually measure squeeze pressure from pelvic diaphragm muscle. Pneumatic resistance chamber used by Kegel was 8 cm long (3) and probably spanned across the entire length of vaginal canal and measured average pressure, rather than true pelvic floor muscle squeeze pressure. Techniques used by other investigators also did not make any attempt to distinguishing pressures from different segments of vaginal canal.
U.S. Pat. No. 6,862,480 discloses a device for training pelvic floor muscles in order to prevent or treat urinary or fecal incontinence. The device comprises a probe having a pressure sensor and a vibrator and a microprocessor connected to the sensor and the vibrator. This device however does not measure the constrictor and elevator function of the pelvic floor muscles. U.S. Pat. Nos. 6,862,480, 6,773,380, 6,562,018 and 6,068,581 describe different devices either for testing or exercising pelvic floor muscles. However none of these devices can measure a both constrictor and elevator function of the pelvic floor muscles and furthermore they do not use the values obtained therein to provide biofeedback therapy to these muscles.
U.S. Pat. No. 6,468,232 describes a device to measure pelvic floor muscle properties using two or more elongated blades disposed adjacent to each other and one or more sensors that can sense the deflection of one blade with respect to another when the blades are subjected to an external force. However the pelvic floor muscles pressure measured by this apparatus includes abdominal pressure and requires a complicated method to arrive at actual pelvic floor muscle forces. Furthermore, this device does not measure the elevator function of the pelvic floor muscles. This device also does not provide a means to offer resistance to pelvic floor muscles in order to exercise these muscles against resistance.
Thus, the prior art lacks a device that can, (1) measure the constrictor and elevator function of the pelvic diaphragm simultaneously; (2) measure the length tension curves of the constrictor and elevator functions of pelvic floor muscle; and (3) interpret such measurements to provide biofeedback therapy if a subject is in need of such therapy. The instant invention fulfills this need in the art.